In the coordinated operation of moving newly formed ware from the forming machine to the annealing lehr, several considerations have to be met. Depending on the number of forming machine sections which are producing ware and the number and size of the ware or containers being produced, the pattern of the ware in the lehr may vary.
Generally speaking, it has been the practice to move newly formed ware from the forming machine sections, such as the IS machine sections, by the sliding of the ware from a dead plate onto a moving conveyor. This moving conveyor is common to all of the machine sections and is generally termed the "machine conveyor". Because the forming machines are becoming more productive due to the fact that single cavity machines have been replaced with plural cavity machines and additional sections are being added to what was considered to be the standard 6-section IS machine, so that a single machine can now produce as many as 320 bottles each minute. The number of containers to be handled and moved into a lehr has dramatically increased in the recent past. It is not uncommon to have eight individual sections in a forming machine producing three containers at a time from each section. Therefore, twenty-four bottles will be produced during one cycle of the machine. These machines may have a rate of twelve cycles per minute.
With the advent of even larger forming machines, such as a 10-section IS machine which, theoretically, could produce thirty containers during a complete machine cycle, it is readily apparent that movement of these containers from the forming machine to a lehr requires precise timing and increased speed to accomplish the task.
Another consideration is the fact that the containers, since they are moving while resting on their bottoms, may in some instances be somewhat unstable and therefore necessarily dictate that there be a limit to the amount of speed and acceleration or deceleration which may be experienced by the bottle or container during transfer to avoid tipping.
One other consideration, when all of the containers are equally spaced and are moving along the machine conveyor in what amounts to a continuous line of ware and the ware is then moved onto a conveyor that moves across the front of the lehr, referred to in the art as a "cross-conveyor", if there are an increasing number of containers being produced, the loading of the containers onto the lehr also has to be at a somewhat accelerated rate. Due to the close spacing of the containers on the cross-conveyor and the sliding movement of the ware from the cross-conveyor being accomplished by a pusher bar, there is the tendency for one end of the bar to tip over the leading one of the advancing containers during the time the pusher bar is moving through the line of ware. To avoid this obvious difficulty, the pusher bar, while moving through the line of ware to push the line of ware onto the lehr, has been provided with a component of movement in the direction of the cross-conveyor movement. This proved to be a fairly successful operation and gave to the bar a slight amount of extra time to clear the ware in advance of the leading container. However, with the ever increasing production rates of larger forming machines, this has, most recently, proved not to be the complete answer.
U.S. Pat. No. 4,067,434 issued Jan. 10, 1978 to E. H. Mumford, is a patent disclosing a lehr loader for pushing a row of glass containers from a cross-conveyor onto a lehr mat and the pusher mechanism is guided such that it does travel in the direction of the moving cross-conveyor during its pushing movement. Because of the speed with which the mechanism has been operated in order to keep up with the production of the ware, the stability of the containers became a problem, since it was necessary to push the ware at a fairly rapid pace; otherwise, the pusher bar would tip the leading container at what may be termed the "cut-off point".
The above-referred-to Mumford patent adds to the general operation of lehr loader, stabilizing bars which, in effect, are intended to maintain the stability of the containers by confining the amount of movement of the neck of the container relative to its base so that the mechanism could be operated at a faster rate than in the past without tipping the unstable containers during transfer to the lehr mat.
Another example of a lehr loader is that of Smith et al., U.S. Pat. No. 2,547,791 issued Apr. 3, 1951. In this patent the loader bar is designed to move straight forward without any side motion. This type of loader was successful where the rate of production was not too fast and the speed of the bar at impact with the line of ware was not too severe. In comparison to the operation of mechanisms that are used to load lehrs at the present time, this Smith et al. patent discloses an apparatus which was effective in its day by loading ware on a lehr where the glassware was being produced at perhaps less than half the production speeds that are now being met.
It can be seen from the foregoing that it is increasingly a problem to operate the lehr loader or its pusher bar so that it may pass through the row of bottles on a cross-conveyor without tipping the ware and without interfering with the movement of the next line of ware coming on the cross-conveyor. It is to this problem that the present invention is directed and the method set forth hereinafter will provide a system of coordinate movement of the machine section sweepout mechanisms, the machine conveyor, ware transfer apparatus and cross-conveyor with the lehr loader so as to provide an improved method for loading containers into a annealing lehr.